1. Field of the Invention
The present invention relates to a micro device and a method for manufacturing the same having an air sealing structure.
2. Description of Related Art
With miniaturization of semiconductor devices recently, micro devices such as micro switches have been produced by semiconductor process as disclosed, for example, in Japanese Patent Laid-Open No. 2001-37763 and WO 02/061781.
FIGS. 1A to 1C show a conventional method for manufacturing a micro switch. At first, as shown in FIG. 1A, a part of the surface of Si substrate 100 is removed by etching to form a concave portion 102. Then, materials are laminated on a bottom face of the concave portion 102 by sputtering or evaporation to form a cantilever 106 of a bimorph structure having a heater 104. Further, conductive materials are laminated on the surface of the cantilever 106 and the side face of the concave portion 102 by sputtering or evaporation to form a lead 108 for supplying electric power to the heater 104. At this time, the lead 108 is formed from the heater 104 to the surface of Si substrate 100.
Next, as shown in FIG. 1B, the bottom face of the concave portion 102 of the Si substrate 100 on which the cantilever 106 is formed is removed by etching to secure a movable area of the cantilever 106. Then, as shown in FIG. 1C, a circuit board 112, on which an electrode pad 110 is formed, is prepared, and the Si substrate 100, in which the cantilever 106 is formed, is adhered to the circuit board 112 so as to seal the cantilever 106 using the Si substrate 100 and the circuit board 112. At this time, the lead 108 and the electrode pad 110 are joined by mechanical pressure bonding so that they are electrically connected to each other. Then, electric power from outside is supplied to the heater 104 via the electrode pad 110 and the lead 108, and thus the cantilever 106 is driven.
In the conventional method for manufacturing a micro switch, since the lead 108 and the electrode pad 110 are joined by mechanical pressure bonding to connect them each other electrically, there was a problem that impedance of a joint point fluctuates. In addition, in order to stably join the lead 108 and the electrode pad 110, depth precision of the concave portion 102 formed by etching and plane precision of an adhered face of the Si substrate 100 and the circuit board 112 are required very strictly.